The effects of panaxadiol saponins on megakaryocytic maturation and immune function in a mouse model of immune thrombocytopenia.

We have identified a biologically active component, panaxadiol saponins component (PDS-C), from Chinese ginseng herb extract. Panaxadiol saponins component contains five ginsenoside monomers with total purity of 92.44%. In this study, the BALB/c mouse model with immune thrombocytopenia (ITP) was established by injection of antiplatelet antibody every other day for 5 total times; the peripheral blood platelet counts steadily decreased to 20%-30% of normal levels and remained decreased for about 10 days. The antiplatelet antibody was derived from the sera of guinea pigs immunized with the platelets of BALB/c mice. Mice with ITP were treated with PDS-C at a low, a moderate, or a high dose for 10 consecutive days. We observed that the peripheral blood platelet counts of ITP mice were significantly higher than that of ITP controls (untreated) after treatment of PDS-C in a dose-dependent manner. Treatment with PDS-C also increased the mature megakaryocytes in the bone marrow of treated ITP animals with a concomitant decease of immature megakaryocyte precursors. Furthermore, macrophage phagocytosis of exogenous erythrocytes in the intra-abdominal cavity of ITP mice was inhibited by PDS-C treatment, indicating that PDS-C also could modulate immune function and may possibly prevent phagocytosis of antibody-coated platelets. Altogether, our findings suggest that PDS-C may have a dual role, promoting proliferation and differentiation of megakaryocytes, as well as modulating immune function, and it may therefore be very helpful in the treatment of ITP.